Part of an industry that apparently the recession forgot, generics firms are pumping money into the local economy, hiring hundreds of employees and fueling construction work, while opening themselves up to acquisitions.

Over-the-counter drug maker LNK International paid about $8 million for a vacant 93,000-square-foot industrial building at 55 Arkay Drive in Hauppauge. LNK will use the building, which has 3,000 square feet of office space and 40,000 square feet of manufacturing ...